491 lines
16 KiB
C
491 lines
16 KiB
C
/*
|
|
* vm86 linux syscall support
|
|
*
|
|
* Copyright (c) 2003 Fabrice Bellard
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
#include "qemu/osdep.h"
|
|
|
|
#include "qemu.h"
|
|
|
|
//#define DEBUG_VM86
|
|
|
|
#ifdef DEBUG_VM86
|
|
# define LOG_VM86(...) qemu_log(__VA_ARGS__);
|
|
#else
|
|
# define LOG_VM86(...) do { } while (0)
|
|
#endif
|
|
|
|
|
|
#define set_flags(X,new,mask) \
|
|
((X) = ((X) & ~(mask)) | ((new) & (mask)))
|
|
|
|
#define SAFE_MASK (0xDD5)
|
|
#define RETURN_MASK (0xDFF)
|
|
|
|
static inline int is_revectored(int nr, struct target_revectored_struct *bitmap)
|
|
{
|
|
return (((uint8_t *)bitmap)[nr >> 3] >> (nr & 7)) & 1;
|
|
}
|
|
|
|
static inline void vm_putw(CPUX86State *env, uint32_t segptr,
|
|
unsigned int reg16, unsigned int val)
|
|
{
|
|
cpu_stw_data(env, segptr + (reg16 & 0xffff), val);
|
|
}
|
|
|
|
static inline void vm_putl(CPUX86State *env, uint32_t segptr,
|
|
unsigned int reg16, unsigned int val)
|
|
{
|
|
cpu_stl_data(env, segptr + (reg16 & 0xffff), val);
|
|
}
|
|
|
|
static inline unsigned int vm_getb(CPUX86State *env,
|
|
uint32_t segptr, unsigned int reg16)
|
|
{
|
|
return cpu_ldub_data(env, segptr + (reg16 & 0xffff));
|
|
}
|
|
|
|
static inline unsigned int vm_getw(CPUX86State *env,
|
|
uint32_t segptr, unsigned int reg16)
|
|
{
|
|
return cpu_lduw_data(env, segptr + (reg16 & 0xffff));
|
|
}
|
|
|
|
static inline unsigned int vm_getl(CPUX86State *env,
|
|
uint32_t segptr, unsigned int reg16)
|
|
{
|
|
return cpu_ldl_data(env, segptr + (reg16 & 0xffff));
|
|
}
|
|
|
|
void save_v86_state(CPUX86State *env)
|
|
{
|
|
CPUState *cs = CPU(x86_env_get_cpu(env));
|
|
TaskState *ts = cs->opaque;
|
|
struct target_vm86plus_struct * target_v86;
|
|
|
|
if (!lock_user_struct(VERIFY_WRITE, target_v86, ts->target_v86, 0))
|
|
/* FIXME - should return an error */
|
|
return;
|
|
/* put the VM86 registers in the userspace register structure */
|
|
target_v86->regs.eax = tswap32(env->regs[R_EAX]);
|
|
target_v86->regs.ebx = tswap32(env->regs[R_EBX]);
|
|
target_v86->regs.ecx = tswap32(env->regs[R_ECX]);
|
|
target_v86->regs.edx = tswap32(env->regs[R_EDX]);
|
|
target_v86->regs.esi = tswap32(env->regs[R_ESI]);
|
|
target_v86->regs.edi = tswap32(env->regs[R_EDI]);
|
|
target_v86->regs.ebp = tswap32(env->regs[R_EBP]);
|
|
target_v86->regs.esp = tswap32(env->regs[R_ESP]);
|
|
target_v86->regs.eip = tswap32(env->eip);
|
|
target_v86->regs.cs = tswap16(env->segs[R_CS].selector);
|
|
target_v86->regs.ss = tswap16(env->segs[R_SS].selector);
|
|
target_v86->regs.ds = tswap16(env->segs[R_DS].selector);
|
|
target_v86->regs.es = tswap16(env->segs[R_ES].selector);
|
|
target_v86->regs.fs = tswap16(env->segs[R_FS].selector);
|
|
target_v86->regs.gs = tswap16(env->segs[R_GS].selector);
|
|
set_flags(env->eflags, ts->v86flags, VIF_MASK | ts->v86mask);
|
|
target_v86->regs.eflags = tswap32(env->eflags);
|
|
unlock_user_struct(target_v86, ts->target_v86, 1);
|
|
LOG_VM86("save_v86_state: eflags=%08x cs:ip=%04x:%04x\n",
|
|
env->eflags, env->segs[R_CS].selector, env->eip);
|
|
|
|
/* restore 32 bit registers */
|
|
env->regs[R_EAX] = ts->vm86_saved_regs.eax;
|
|
env->regs[R_EBX] = ts->vm86_saved_regs.ebx;
|
|
env->regs[R_ECX] = ts->vm86_saved_regs.ecx;
|
|
env->regs[R_EDX] = ts->vm86_saved_regs.edx;
|
|
env->regs[R_ESI] = ts->vm86_saved_regs.esi;
|
|
env->regs[R_EDI] = ts->vm86_saved_regs.edi;
|
|
env->regs[R_EBP] = ts->vm86_saved_regs.ebp;
|
|
env->regs[R_ESP] = ts->vm86_saved_regs.esp;
|
|
env->eflags = ts->vm86_saved_regs.eflags;
|
|
env->eip = ts->vm86_saved_regs.eip;
|
|
|
|
cpu_x86_load_seg(env, R_CS, ts->vm86_saved_regs.cs);
|
|
cpu_x86_load_seg(env, R_SS, ts->vm86_saved_regs.ss);
|
|
cpu_x86_load_seg(env, R_DS, ts->vm86_saved_regs.ds);
|
|
cpu_x86_load_seg(env, R_ES, ts->vm86_saved_regs.es);
|
|
cpu_x86_load_seg(env, R_FS, ts->vm86_saved_regs.fs);
|
|
cpu_x86_load_seg(env, R_GS, ts->vm86_saved_regs.gs);
|
|
}
|
|
|
|
/* return from vm86 mode to 32 bit. The vm86() syscall will return
|
|
'retval' */
|
|
static inline void return_to_32bit(CPUX86State *env, int retval)
|
|
{
|
|
LOG_VM86("return_to_32bit: ret=0x%x\n", retval);
|
|
save_v86_state(env);
|
|
env->regs[R_EAX] = retval;
|
|
}
|
|
|
|
static inline int set_IF(CPUX86State *env)
|
|
{
|
|
CPUState *cs = CPU(x86_env_get_cpu(env));
|
|
TaskState *ts = cs->opaque;
|
|
|
|
ts->v86flags |= VIF_MASK;
|
|
if (ts->v86flags & VIP_MASK) {
|
|
return_to_32bit(env, TARGET_VM86_STI);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static inline void clear_IF(CPUX86State *env)
|
|
{
|
|
CPUState *cs = CPU(x86_env_get_cpu(env));
|
|
TaskState *ts = cs->opaque;
|
|
|
|
ts->v86flags &= ~VIF_MASK;
|
|
}
|
|
|
|
static inline void clear_TF(CPUX86State *env)
|
|
{
|
|
env->eflags &= ~TF_MASK;
|
|
}
|
|
|
|
static inline void clear_AC(CPUX86State *env)
|
|
{
|
|
env->eflags &= ~AC_MASK;
|
|
}
|
|
|
|
static inline int set_vflags_long(unsigned long eflags, CPUX86State *env)
|
|
{
|
|
CPUState *cs = CPU(x86_env_get_cpu(env));
|
|
TaskState *ts = cs->opaque;
|
|
|
|
set_flags(ts->v86flags, eflags, ts->v86mask);
|
|
set_flags(env->eflags, eflags, SAFE_MASK);
|
|
if (eflags & IF_MASK)
|
|
return set_IF(env);
|
|
else
|
|
clear_IF(env);
|
|
return 0;
|
|
}
|
|
|
|
static inline int set_vflags_short(unsigned short flags, CPUX86State *env)
|
|
{
|
|
CPUState *cs = CPU(x86_env_get_cpu(env));
|
|
TaskState *ts = cs->opaque;
|
|
|
|
set_flags(ts->v86flags, flags, ts->v86mask & 0xffff);
|
|
set_flags(env->eflags, flags, SAFE_MASK);
|
|
if (flags & IF_MASK)
|
|
return set_IF(env);
|
|
else
|
|
clear_IF(env);
|
|
return 0;
|
|
}
|
|
|
|
static inline unsigned int get_vflags(CPUX86State *env)
|
|
{
|
|
CPUState *cs = CPU(x86_env_get_cpu(env));
|
|
TaskState *ts = cs->opaque;
|
|
unsigned int flags;
|
|
|
|
flags = env->eflags & RETURN_MASK;
|
|
if (ts->v86flags & VIF_MASK)
|
|
flags |= IF_MASK;
|
|
flags |= IOPL_MASK;
|
|
return flags | (ts->v86flags & ts->v86mask);
|
|
}
|
|
|
|
#define ADD16(reg, val) reg = (reg & ~0xffff) | ((reg + (val)) & 0xffff)
|
|
|
|
/* handle VM86 interrupt (NOTE: the CPU core currently does not
|
|
support TSS interrupt revectoring, so this code is always executed) */
|
|
static void do_int(CPUX86State *env, int intno)
|
|
{
|
|
CPUState *cs = CPU(x86_env_get_cpu(env));
|
|
TaskState *ts = cs->opaque;
|
|
uint32_t int_addr, segoffs, ssp;
|
|
unsigned int sp;
|
|
|
|
if (env->segs[R_CS].selector == TARGET_BIOSSEG)
|
|
goto cannot_handle;
|
|
if (is_revectored(intno, &ts->vm86plus.int_revectored))
|
|
goto cannot_handle;
|
|
if (intno == 0x21 && is_revectored((env->regs[R_EAX] >> 8) & 0xff,
|
|
&ts->vm86plus.int21_revectored))
|
|
goto cannot_handle;
|
|
int_addr = (intno << 2);
|
|
segoffs = cpu_ldl_data(env, int_addr);
|
|
if ((segoffs >> 16) == TARGET_BIOSSEG)
|
|
goto cannot_handle;
|
|
LOG_VM86("VM86: emulating int 0x%x. CS:IP=%04x:%04x\n",
|
|
intno, segoffs >> 16, segoffs & 0xffff);
|
|
/* save old state */
|
|
ssp = env->segs[R_SS].selector << 4;
|
|
sp = env->regs[R_ESP] & 0xffff;
|
|
vm_putw(env, ssp, sp - 2, get_vflags(env));
|
|
vm_putw(env, ssp, sp - 4, env->segs[R_CS].selector);
|
|
vm_putw(env, ssp, sp - 6, env->eip);
|
|
ADD16(env->regs[R_ESP], -6);
|
|
/* goto interrupt handler */
|
|
env->eip = segoffs & 0xffff;
|
|
cpu_x86_load_seg(env, R_CS, segoffs >> 16);
|
|
clear_TF(env);
|
|
clear_IF(env);
|
|
clear_AC(env);
|
|
return;
|
|
cannot_handle:
|
|
LOG_VM86("VM86: return to 32 bits int 0x%x\n", intno);
|
|
return_to_32bit(env, TARGET_VM86_INTx | (intno << 8));
|
|
}
|
|
|
|
void handle_vm86_trap(CPUX86State *env, int trapno)
|
|
{
|
|
if (trapno == 1 || trapno == 3) {
|
|
return_to_32bit(env, TARGET_VM86_TRAP + (trapno << 8));
|
|
} else {
|
|
do_int(env, trapno);
|
|
}
|
|
}
|
|
|
|
#define CHECK_IF_IN_TRAP() \
|
|
if ((ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_active) && \
|
|
(ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_TFpendig)) \
|
|
newflags |= TF_MASK
|
|
|
|
#define VM86_FAULT_RETURN \
|
|
if ((ts->vm86plus.vm86plus.flags & TARGET_force_return_for_pic) && \
|
|
(ts->v86flags & (IF_MASK | VIF_MASK))) \
|
|
return_to_32bit(env, TARGET_VM86_PICRETURN); \
|
|
return
|
|
|
|
void handle_vm86_fault(CPUX86State *env)
|
|
{
|
|
CPUState *cs = CPU(x86_env_get_cpu(env));
|
|
TaskState *ts = cs->opaque;
|
|
uint32_t csp, ssp;
|
|
unsigned int ip, sp, newflags, newip, newcs, opcode, intno;
|
|
int data32, pref_done;
|
|
|
|
csp = env->segs[R_CS].selector << 4;
|
|
ip = env->eip & 0xffff;
|
|
|
|
ssp = env->segs[R_SS].selector << 4;
|
|
sp = env->regs[R_ESP] & 0xffff;
|
|
|
|
LOG_VM86("VM86 exception %04x:%08x\n",
|
|
env->segs[R_CS].selector, env->eip);
|
|
|
|
data32 = 0;
|
|
pref_done = 0;
|
|
do {
|
|
opcode = vm_getb(env, csp, ip);
|
|
ADD16(ip, 1);
|
|
switch (opcode) {
|
|
case 0x66: /* 32-bit data */ data32=1; break;
|
|
case 0x67: /* 32-bit address */ break;
|
|
case 0x2e: /* CS */ break;
|
|
case 0x3e: /* DS */ break;
|
|
case 0x26: /* ES */ break;
|
|
case 0x36: /* SS */ break;
|
|
case 0x65: /* GS */ break;
|
|
case 0x64: /* FS */ break;
|
|
case 0xf2: /* repnz */ break;
|
|
case 0xf3: /* rep */ break;
|
|
default: pref_done = 1;
|
|
}
|
|
} while (!pref_done);
|
|
|
|
/* VM86 mode */
|
|
switch(opcode) {
|
|
case 0x9c: /* pushf */
|
|
if (data32) {
|
|
vm_putl(env, ssp, sp - 4, get_vflags(env));
|
|
ADD16(env->regs[R_ESP], -4);
|
|
} else {
|
|
vm_putw(env, ssp, sp - 2, get_vflags(env));
|
|
ADD16(env->regs[R_ESP], -2);
|
|
}
|
|
env->eip = ip;
|
|
VM86_FAULT_RETURN;
|
|
|
|
case 0x9d: /* popf */
|
|
if (data32) {
|
|
newflags = vm_getl(env, ssp, sp);
|
|
ADD16(env->regs[R_ESP], 4);
|
|
} else {
|
|
newflags = vm_getw(env, ssp, sp);
|
|
ADD16(env->regs[R_ESP], 2);
|
|
}
|
|
env->eip = ip;
|
|
CHECK_IF_IN_TRAP();
|
|
if (data32) {
|
|
if (set_vflags_long(newflags, env))
|
|
return;
|
|
} else {
|
|
if (set_vflags_short(newflags, env))
|
|
return;
|
|
}
|
|
VM86_FAULT_RETURN;
|
|
|
|
case 0xcd: /* int */
|
|
intno = vm_getb(env, csp, ip);
|
|
ADD16(ip, 1);
|
|
env->eip = ip;
|
|
if (ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_active) {
|
|
if ( (ts->vm86plus.vm86plus.vm86dbg_intxxtab[intno >> 3] >>
|
|
(intno &7)) & 1) {
|
|
return_to_32bit(env, TARGET_VM86_INTx + (intno << 8));
|
|
return;
|
|
}
|
|
}
|
|
do_int(env, intno);
|
|
break;
|
|
|
|
case 0xcf: /* iret */
|
|
if (data32) {
|
|
newip = vm_getl(env, ssp, sp) & 0xffff;
|
|
newcs = vm_getl(env, ssp, sp + 4) & 0xffff;
|
|
newflags = vm_getl(env, ssp, sp + 8);
|
|
ADD16(env->regs[R_ESP], 12);
|
|
} else {
|
|
newip = vm_getw(env, ssp, sp);
|
|
newcs = vm_getw(env, ssp, sp + 2);
|
|
newflags = vm_getw(env, ssp, sp + 4);
|
|
ADD16(env->regs[R_ESP], 6);
|
|
}
|
|
env->eip = newip;
|
|
cpu_x86_load_seg(env, R_CS, newcs);
|
|
CHECK_IF_IN_TRAP();
|
|
if (data32) {
|
|
if (set_vflags_long(newflags, env))
|
|
return;
|
|
} else {
|
|
if (set_vflags_short(newflags, env))
|
|
return;
|
|
}
|
|
VM86_FAULT_RETURN;
|
|
|
|
case 0xfa: /* cli */
|
|
env->eip = ip;
|
|
clear_IF(env);
|
|
VM86_FAULT_RETURN;
|
|
|
|
case 0xfb: /* sti */
|
|
env->eip = ip;
|
|
if (set_IF(env))
|
|
return;
|
|
VM86_FAULT_RETURN;
|
|
|
|
default:
|
|
/* real VM86 GPF exception */
|
|
return_to_32bit(env, TARGET_VM86_UNKNOWN);
|
|
break;
|
|
}
|
|
}
|
|
|
|
int do_vm86(CPUX86State *env, long subfunction, abi_ulong vm86_addr)
|
|
{
|
|
CPUState *cs = CPU(x86_env_get_cpu(env));
|
|
TaskState *ts = cs->opaque;
|
|
struct target_vm86plus_struct * target_v86;
|
|
int ret;
|
|
|
|
switch (subfunction) {
|
|
case TARGET_VM86_REQUEST_IRQ:
|
|
case TARGET_VM86_FREE_IRQ:
|
|
case TARGET_VM86_GET_IRQ_BITS:
|
|
case TARGET_VM86_GET_AND_RESET_IRQ:
|
|
gemu_log("qemu: unsupported vm86 subfunction (%ld)\n", subfunction);
|
|
ret = -TARGET_EINVAL;
|
|
goto out;
|
|
case TARGET_VM86_PLUS_INSTALL_CHECK:
|
|
/* NOTE: on old vm86 stuff this will return the error
|
|
from verify_area(), because the subfunction is
|
|
interpreted as (invalid) address to vm86_struct.
|
|
So the installation check works.
|
|
*/
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/* save current CPU regs */
|
|
ts->vm86_saved_regs.eax = 0; /* default vm86 syscall return code */
|
|
ts->vm86_saved_regs.ebx = env->regs[R_EBX];
|
|
ts->vm86_saved_regs.ecx = env->regs[R_ECX];
|
|
ts->vm86_saved_regs.edx = env->regs[R_EDX];
|
|
ts->vm86_saved_regs.esi = env->regs[R_ESI];
|
|
ts->vm86_saved_regs.edi = env->regs[R_EDI];
|
|
ts->vm86_saved_regs.ebp = env->regs[R_EBP];
|
|
ts->vm86_saved_regs.esp = env->regs[R_ESP];
|
|
ts->vm86_saved_regs.eflags = env->eflags;
|
|
ts->vm86_saved_regs.eip = env->eip;
|
|
ts->vm86_saved_regs.cs = env->segs[R_CS].selector;
|
|
ts->vm86_saved_regs.ss = env->segs[R_SS].selector;
|
|
ts->vm86_saved_regs.ds = env->segs[R_DS].selector;
|
|
ts->vm86_saved_regs.es = env->segs[R_ES].selector;
|
|
ts->vm86_saved_regs.fs = env->segs[R_FS].selector;
|
|
ts->vm86_saved_regs.gs = env->segs[R_GS].selector;
|
|
|
|
ts->target_v86 = vm86_addr;
|
|
if (!lock_user_struct(VERIFY_READ, target_v86, vm86_addr, 1))
|
|
return -TARGET_EFAULT;
|
|
/* build vm86 CPU state */
|
|
ts->v86flags = tswap32(target_v86->regs.eflags);
|
|
env->eflags = (env->eflags & ~SAFE_MASK) |
|
|
(tswap32(target_v86->regs.eflags) & SAFE_MASK) | VM_MASK;
|
|
|
|
ts->vm86plus.cpu_type = tswapal(target_v86->cpu_type);
|
|
switch (ts->vm86plus.cpu_type) {
|
|
case TARGET_CPU_286:
|
|
ts->v86mask = 0;
|
|
break;
|
|
case TARGET_CPU_386:
|
|
ts->v86mask = NT_MASK | IOPL_MASK;
|
|
break;
|
|
case TARGET_CPU_486:
|
|
ts->v86mask = AC_MASK | NT_MASK | IOPL_MASK;
|
|
break;
|
|
default:
|
|
ts->v86mask = ID_MASK | AC_MASK | NT_MASK | IOPL_MASK;
|
|
break;
|
|
}
|
|
|
|
env->regs[R_EBX] = tswap32(target_v86->regs.ebx);
|
|
env->regs[R_ECX] = tswap32(target_v86->regs.ecx);
|
|
env->regs[R_EDX] = tswap32(target_v86->regs.edx);
|
|
env->regs[R_ESI] = tswap32(target_v86->regs.esi);
|
|
env->regs[R_EDI] = tswap32(target_v86->regs.edi);
|
|
env->regs[R_EBP] = tswap32(target_v86->regs.ebp);
|
|
env->regs[R_ESP] = tswap32(target_v86->regs.esp);
|
|
env->eip = tswap32(target_v86->regs.eip);
|
|
cpu_x86_load_seg(env, R_CS, tswap16(target_v86->regs.cs));
|
|
cpu_x86_load_seg(env, R_SS, tswap16(target_v86->regs.ss));
|
|
cpu_x86_load_seg(env, R_DS, tswap16(target_v86->regs.ds));
|
|
cpu_x86_load_seg(env, R_ES, tswap16(target_v86->regs.es));
|
|
cpu_x86_load_seg(env, R_FS, tswap16(target_v86->regs.fs));
|
|
cpu_x86_load_seg(env, R_GS, tswap16(target_v86->regs.gs));
|
|
ret = tswap32(target_v86->regs.eax); /* eax will be restored at
|
|
the end of the syscall */
|
|
memcpy(&ts->vm86plus.int_revectored,
|
|
&target_v86->int_revectored, 32);
|
|
memcpy(&ts->vm86plus.int21_revectored,
|
|
&target_v86->int21_revectored, 32);
|
|
ts->vm86plus.vm86plus.flags = tswapal(target_v86->vm86plus.flags);
|
|
memcpy(&ts->vm86plus.vm86plus.vm86dbg_intxxtab,
|
|
target_v86->vm86plus.vm86dbg_intxxtab, 32);
|
|
unlock_user_struct(target_v86, vm86_addr, 0);
|
|
|
|
LOG_VM86("do_vm86: cs:ip=%04x:%04x\n",
|
|
env->segs[R_CS].selector, env->eip);
|
|
/* now the virtual CPU is ready for vm86 execution ! */
|
|
out:
|
|
return ret;
|
|
}
|